You Seem To Have A Darkness Problem
by Unformal Sorrelle
Summary: "Henry stared at the creature in front of him. It was almost like Peter Pan's shadow, but more… cartoony if that was the right word. Yes, the thing was certainly humanoid but small, with strange pointy feet and glowing yellow eyes. It would have been cute if the rest of its kind weren't attacking Storybrooke." In which Heartless, Keyblades, and Xehanort invade Storybrooke.


You Seem To Have A Darkness Problem

Part One

 _A Kingdom Hearts x Once Upon a Time Crossover_

Or basically Darkness, Hearts, and Disney Characters

* * *

Henry stared at the creature in front of him. It was almost like Peter Pan's shadow, but more… cartoony if that was the right word. Yes, the thing was certainly humanoid but small, with strange pointy feet and glowing yellow eyes. It would have been cute if the rest of its kind weren't attacking Storybrooke.

Grandpa Charming had tried to get him to safety, and his mom thought that the protections of her mansion would keep these monsters out, but it wasn't to be apparently. Everyone was away, fighting for the town or being a Dark One. He'd half to deal with this one by himself.

Ok, he could probably call Emma with her Dark One powers and she'd come teleporting in a puff of dark smoke but he wasn't sure he could trust her. He hated to admit it, but recently his mom had been creeping him out. Possession by darkness had changed her and while Henry wasn't giving up on her, not ever, he wasn't sure he wanted to call her to his rescue. For all he knew, his mom had created these things to wreck her 'vengeance' on them all.

But it wasn't like he was a kid anymore. He could handle one of these monsters by himself. He was the Author! Renounced and all, as well as weaponless, but he wasn't going to be a victim. He came from a long line of Disney characters, heroes and villains alike. Henry knew he was capable so if he could just find something…

His eyes flickered around his other mom's office for some sort of weapon. Unfortunately, his mom didn't have anything convenient like a sword on the wall. He knew this room too well and gritted his teeth when something didn't magically come to him. The best he had was the chair.

The shadow creature melted into the floor, coming back up when it had moved a yard closer. It's dumb, unblinking eyes looked never left him as it seemed to fall back into its shuttering unbalanced dance.

Could he even hurt the monster? He wasn't sure if it was actually a liquid or somehow a being made of shadows, but if it could turn into a puddle then he didn't see that banging it with a chair would accomplish anything.

It's times like these where Henry wished he knew how to throw fireballs.

He could probably outrun the shadow creature. Going outside was probably a bad idea with the streets full of these creatures but maybe he could run around the house. Maybe if he found some duct tape then he could actually shadow-proof a door so it wouldn't go under it again. See, he could handle it!

The shadow wobbled in such a way that Henry had to wonder if it was sick or something. Or perhaps, due to its ability to melt, it didn't have proper bones to hold it up? But it seemed solid enough when it had taken someone's heart…

Aliens, Henry shook his head as it sunk into the floor again. Or magic, or beings from another world, ect. It was pretty much all the same as anything else that didn't operate within the rules of The World Without Magic. The laws of reality were more flexible to the universe at large then they were in the place he had grown up in. He supposed this made Earth the weird one. He also wondered if having Storybrooke as a rare spot with magic in this world had let the creatures invade his little town instead of something like New York.

But then he didn't watch the news, so there could very well be monsters attacking New York right now. Doubtful, yes- but entirely possible.

Watching the blob very carefully, Henry took his mom's office chair as a shield in front of him and crabwalked towards the door. He had a passing thought about rolling the chair over the creature when it was in the weird liquidy spot-on-the-floor state and seeing if it could get tangled up in the wheels but it… probably wasn't the best idea. For all he knew it could posses the chair.

No, he didn't read too much fiction. Or play too many videogames. With the life he lived they were actually very practical research material. Yes.

With a sigh of relief, and a foreboding feeling in his gut, he made it safely to the door. The shadow was back to its three dimensional body and staring at him, so Henry figured this would have to be quick. He opened the door. When his first glance revealed an armored monster he growled and didn't _slam_ the door. But it was close.

From what his limited observation had provided, the shadow-like ones were the weakest. There were more of them than the others and they were slow, they hid. If they got in a group they could swarm, but individually they were more careful. The armored creatures however, they just attacked. They tended to run in packs, and his family had trouble finding out exactly where they could hit them. Worse yet was everything else; the fat ones, the hated mages, the plant things…

Perhaps having a room with a single shadow wasn't that bad when he thought about it…

Henry all but ran to the desk, pushing the chair in the opposite direction for cover. The shadow was startled into blobdom yet again, but it sprang back up and it was looking hungry.

"This isn't good…" Henry searched his mom's desk again, looking for something more frightening than a stapler. He knew the shadow was an opportunistic coward. He needed to use that. If he scared it then hopefully it'd leave him be.

Why was his mom's office so sleek and modern? Why couldn't there be dangerous looking clutter? Sure, some of the shiny silver objects looked sharp but that wasn't going to work. All the chairs in the rooms were useless without a good plan. He couldn't just chuck apples at it.

Suddenly, as if sensing his fear, the shadow lunged at him. Henry jumped to the side as he pushed the desk towards it. Unfortunately, it didn't even hit the thing or slow it down. It was loud though, too loud, and Henry worried that the clatter of all Mom's stuff would attract even more monsters.

It was almost to the point where he would risk calling Emma.

What could he do? As the thing seemed to be reacting to his panic, all plans of scaring it were probably off. He still didn't see any potential weapons.

Henry kept moving around the room and the shadow distressingly enough didn't stop in its pouncing. Its grasping claws had gotten too close for comfort and the office was becoming hard to maneuver in with all the displaced furniture. He hadn't paid enough attention and realized quickly when he'd backed himself into a corner. Henry didn't have time to think before the shadow sprang up next to him and made a swipe at him. His higher brain functions utterly shocked into nothing but survival, he kicked its belly and when it was reeling moved to punch it in the face. And that's when things got weird.

Henry didn't expect physically fighting it to work. It was a magical creature, something that even weapons couldn't bring down. It was a last ditch attempt and if he had been thinking he'd be calling the name of anyone vaguely magical in this town.

Instead, a light appeared in his hand. It was a feeling similar to when he'd released the former author from the door. Magic, or something of that sort.

His fist opened slightly to grasp smooth metal, and there was a weight that wasn't there before. Instead of hitting the monster, he found that he'd bashed it with a giant old-fashioned key.

What.

There was no time to think as the shadow attacked again. Instinctively, he blocked the claw with the key and followed through by hitting it once more on the head, right between its antennae. He let his sword training take over and what quite shocked when the monster flashed with white light a disappeared. Did it explode or…?

Then he had to process that he was pretty sure he'd just killed the thing with a giant key that had appeared out of nowhere.

Henry's heart was racing as he looked at the apparent weapon in his hands. It was mostly red, white, and gold, looking like the most complex key he'd ever seen. The handle looked almost like an apple, and he was holding it from what looked like an arrow going through it. The actual blade of the key was gold until it reached a swan at the end. The teeth were comprised by the swan's wings, a crown, a hook, and flames which seemed to make the entire key glow.

At the end, attached by chain, was a copy of his author's pen that he had snapped.

It was a Keyblade. He didn't know how he knew this.

It freaked him out but mostly as he held it felt awesome. There was a weight to it, he knew it was power. It was like his pen, except this time it didn't feel tainted or heavy. The Keyblade felt natural, necessary even.

And he could fight the creatures invading town with it. Even more, he knew he had too.

Especially since they were now swarming him. That wasn't good.

…

Sora, Kairi, and Riku were actually traveling together for once. Temporarily, but they figured after they had all ran into each other in Atlantis that they could take on one world with just them. After all, they'd been busy fighting recently and it was hard to communicate from different worlds. They hadn't talked in forever which was odd after getting a year of peace together on the Islands. Donald, Goofy, and the King also missed each other so they all agreed that it'd be perfectly fine to meet back up at Olympus Coliseum in a week.

This world was weird. Everyone agreed on that. The navigational system labeled it as 'Storybrooke/c/Land_Without_Magic' which was atypical to say the least. Heck, just looking at the data to find it was glitchy. Neither of the trio had any idea what some of those errors were and Sora kept getting accused of breaking the gummiship.

"I don't know if we should land." Riku had argued,

"But there are Heartless swarming, it wouldn't be right to just leave the world to be eaten!" Sora had said.

Kairi had ended it by pointing out that there was probably a reason that this world of all worlds had gotten three Keyblade bearers to take care of it. The world needed them.

Riku conceded and they'd come down to see a town under heavy invasion conditions.

Usually when they got to a town, yes there were Heartless, but people weren't fighting them in the streets. In fact, the worlds tended to be mostly empty. Storybrooke was certainly not empty.

Looking around, this was a world closer to the town of Radiant Garden than anything else. The streets were paved, and the buildings were painted. A large clock tower stood proudly reminding Kairi of when she'd went to Neverland's London. Yet, for all its architecture it still seemed a little old and faded somehow. Timeless.

Well, it would without the scorch marks and Heartless. There were also faint signs of repairs scattered around, leaving Kairi to wonder how much trouble this Storybrooke got into.

There was a dark haired woman throwing fireballs standing in front of a yellow car and a man shooting arrows from behind it. Some people had swords swinging in a chaotic melee in the middle of the road. There was a wolf attempting to tear a shadow apart. One man even shorter than Sora seemed to act as the town crier and announced their foreign presence rather accusatorily.

They actually weren't doing bad for people who had no way to actual kill Heartless.

"We're here to help," Sora smiled as he took on a soldier. The short man grumbled until the Heartless actually died. Kairi tried not to smirk as the group looked at her goofy friend with new found respect. She loved how quickly Sora could integrate himself into a group. It was a different side of him that didn't appear on the islands. But strangers, they actually saw Sora for the hero he was instead of the easygoing kid who'd pulled a disappearing act.

"You know what these things are?" The fireball woman looked at them appraisingly, obviously demanding an answer. Her mouth was pinched and she was still suspicious. Kairi could relate, Heartless tended to do that to a person.

"Yes," said Riku coolly after he dispatched a few shadows with a spell of his own, "They are called Heartless."

"Heartless?" a light haired man with a sword asked. Kairi gasped slightly as she saw Blue Rhapsody float in, about to attack a hook handed man from behind. Quickly, with a dash and a double jump she managed to strike it before it could freeze the man. The man, almost falling over from his attempt to get out of her way, looked at where the Heartless used to be and back at her. He smiled a thanks even as his eyes clearly screamed 'get me out of this mad world' as he got back into a fighting position.

Kairi used a faith spell to banish the remaining Heartless in the near vicinity. She was glad that they all seemed to be weaker varieties so hopefully, despite the number in this world, this wouldn't be too dangerous a world. Quite a few of the onlookers looked pretty shocked at the ease that they had killed the creatures. Kairi guessed, given how weary they all looked, that they'd been fighting for quite a while.

"How did you…?" Fireball was looking scary as she looked at them, "What are Heartless?"

The trio looked at each other, and Riku stepped closer to the other group. He gave the best "darkness of the heart" speech. Sora tended to skirt the edge of revealing the existence of things people ought not to know a bit too closely while Kairi was never sure exactly what to say. Riku was also tall enough that adults tended to respect him more.

The townspeople listened, some looking understanding while others looked suspicious. Before they could start arguing Sora used all the friendly charm he had to get everyone to make introductions. It was strange how cautious these people were.

Regina was the one with magic and a sharp tongue. She also asked the most controversial question they'd heard in a while. "And what world are they from?"

The trio's eyebrows went up.

"How do you know about other worlds?" Kairi asked. There were so few that knew the truth that it'd be a relief not to have to walk on lies of omission. She still didn't know why other worlds was such a secret other that it was 'the Rules'. She'd grown up knowing, and while people Destiny Islands couldn't travel to other worlds- well, until their rafting adventure- the Islanders weren't concerned that they weren't the only world. Why was it ok for places like Disney Castle to know, but not The Land of Dragons? Especially when Heartless and the like tended to spill the beans?

"We are from The Enchanted Forest," Snow stated, which meant nothing to Kairi. Glancing at her friends, she didn't see any recognition from them either. "Well, most of us…"

"Thanks," Hook commented, a wicked grin on his face. Kairi honestly didn't know what to make of meeting yet another man with a hook hand go by the imaginative moniker of 'Hook' but at least this one didn't have a perm.

"We've had experience," Regina summarized shortly, "And don't avoid the question Red Head, who's attacking us?"

Kairi's eyes widened, not sure if the nickname was supposed to be offensive as they'd just been introduced or not. She didn't really mind, but Regina was slightly intimidating. Kairi hoped that they could be friends.

"Uhhh…" Sora started, "Well, they're Heartless. So, it just depends on who's commanding them. Maleficent and Pete are focusing on something else at the moment, and Xehanort is-" Kairi didn't miss how they all tensed at Maleficent's name. Neither did Riku who apparently decided Sora was getting a little off track.

"Heartless want to eat as many hearts as they can, including the heart of the world. Sometimes they're called by someone with darkness but other times they just drop out of the sky if they can find a way in."

"They're pests." Kairi agreed,

Regina scowled, "Darkness, eh?" She then looked at Snow and Charming with a knowing look.

"I'm sure she wouldn't!" Snow argued, "She couldn't."

Regina looked upset and she cynically pronounced, "We have no idea what the Dark One will do."

"The Dark One?" Riku's voice lowered. That didn't sound good at all.

"Recently," Charming hesitated, "Our daughter was possessed by darkness. She was handling it but now…"

Kairi had the sudden impulse to give her friends a hug, both of them. She understood, as much as someone without darkness ever could, the damage that darkness could leave. Possession was terrible. Riku still had nightmares, even when he claimed that he was ok, that it had been a long time ago. She still knew, every time she saw him struggle with his revulsion for the darkness he was left with that Ansem's shade would never truly leave him alone. And Sora… Sora may smile a lot but she knew him and he was still freaked out from Xehanort's possession scheme. This probably hit them a little too closely.

"Swan's gone off the deep end." Regina pulled no punches. "If anyone called these creatures to Storybrooke it'd be her."

Hook visibly bristled at this but Robin grabbed his arm, "Calm down, we all know it's not Emma's fault."

Regina rolled her eyes but there seemed to be a great sadness along with the anger. Kairi bit her lip in sympathy. When she noticed Riku staring off into the distance she lightly bumped his arm, a gesture that appeared accidental, bringing him back. She then stretched her arm out and brushed against Sora's for good measure.

"How come we couldn't hurt the Heartless?" Charming changed the subject, to which Kairi was grateful. She wanted to help their possessed loved one but that just brought up the Xehanort problem that none of them knew how to remove something from a heart. She'd much rather have Riku and Sora talk about Keyblades than think about how they could free a heart from darkness. Kairi got enough of that dilemma from Axel- or uh, Lea.

Sora held up his Keyblade and began to explain.

…

Henry was breathing hard and was surprised he was still alive. He'd fought his way out of the house, and was trying to make his way to his family to help, but the creatures wouldn't leave him alone. He'd walk into an area and they'd appear in numbers.

Not only was he getting tired, even though occasionally he'd get the odd shot of energy after defeating a monster, but they'd gotten a few hits in. He not only was cut and bruised, but a little singed as well. He was just glad he hadn't been struck by any lightning yet. He really didn't think he could survive that.

At this point, he needed to find someone before he got hopelessly outnumbered. There were too many creatures, too many things attacking him.

He stabbed at the last monster in the group, trying not to wheeze as it disappeared. He stood for a moment trying to catch his breath. It'd also be helpful if his blood stopped pumping quite so loudly.

"C'mon," Henry muttered to himself, "I can do this."

He was getting entirely too tempted at this point to call Emma to see if she'd taxi him over. Just imagine that conversation, 'Emma? Mom? Dark One? Heyyy, I know you want to make everyone pay for whatever we did a few weeks ago that we can't remember but I want you to teleport me over to our family. Please? If all these monsters aren't your fault? You can't really expect me to fight them all off with a key, do you? C'mon, Grandpa spent 300 years trying to get to Dad so it's not like Dark One's have to hate their children, right?'

Not a good idea if he was only tired.

But his mom couldn't be too bad to him, could she? If Grandpa was anything to go by?

But the Dark Curse never had Rumplestiltskin's hair turn white, so he probably wasn't the best baseline in regards to Emma. Even if Emma had said that she wasn't mad at _him_ didn't mean she wouldn't use him against the rest of his family. Life was so much easier when he didn't have an evil parent.

Henry stretched a little, cracking his neck loudly enough to scare him a little. His current strategy wasn't working, he was getting far too exhausted too quickly and the monster groups kept growing larger. He didn't have too far to go, but it was getting dicey. One wrong move and magic key or no magic key he'd be a goner.

He took a few steps to the left and leaned against a parked car. If only he knew how to hotwire it… His eyes narrowed and he took out his phone. He'd tried to call his family before but either Storybrooke's spotty cell reception was making it difficult or the not entirely technologically comfortable Enchanted Forestians (and Hook) completely overlooked the strange talking box in a fight. Or they had lost them in Camelot. There were so many possibilities that Henry couldn't think too much on it. But he had his phone, and _yes_ that was LTE signal. So he googled "how to hotwire a car" and wished for the best.

He soon realized that there were… a bit too many results. And then most of them required more than a giant key. Too bad that couldn't unlock the car door- _Wait, what?_

As soon as Henry had that joking thought he found himself pointing his Keyblade at the car. A light shot out and the door opened slightly.

"Cool…" Henry appraised cautiously, inspecting the lock mechanism. It wasn't damaged at all, it was as perfect as if unlocked with a key. Well its key, not a giant magic one that could destroy monsters. "But… suddenly I don't think so."

The unlocking was cool and all but if his key could get in, then what about the monsters? He couldn't fight and drive at the same time, even if his Keyblade could somehow magically start the ignition. He slammed the red door shut and narrowed his eyes in determination. He'd just have to run for it.

As long as he made it to his mom in time for her to throw some magic at the hoard of creatures that would no doubt be chasing him he'd be fine. If not… Perhaps his Keyblade had more tricks hidden up its keychain.

"Here goes nothing," he breathed in a deep breath and started running for Main Street.

He heard the sounds of the monsters appearing; saw the smoky blackness at the edge of his vision. He didn't dare stop. His heart was pounding and he actually preferred it to the strange teleportation noise of the creatures.

It isn't that far, he reminded himself. Storybrooke is tiny, he praised. He didn't even know how many times he'd walked this towns streets, they were so familiar. This was the place he'd grown up. The real place, not like those lies of New York that still messed around with him memory. These monsters had attacked him on his turf and he'd make them regret that.

He reached Main Street, chest heaving, and almost panicked when he didn't see his family. Why hadn't he considered that they could move!? Or, or… No he wouldn't think like that.

But those monsters' kills didn't leave a body.

There was a boy in front of the clock tower surrounded by creatures. As Henry jogged closer, not risking a view at the army of monsters that were surely behind him, he noticed the boy could actually kill the things. Another Keyblade…

The other boy was somehow able to shoot magic from the key, a furious blast of electricity that destroyed most of the monsters in his path. Henry decided that he was going to learn how to do that.

"Uh, hey! A little help here?" Henry yelled out, trying to not sound terrified. The boy didn't raise an eyebrow, but grinned and ran towards him. Henry decided that with this awesome stranger with Thor-power he could finally risk turning around.

Huh. Not as many as he feared.

That didn't mean that there still weren't a lot of them.

Luckily the other boy was scarily efficient. Henry could barely get in a few blunt hits with his vision tinged black at the edges. He was definitely going to sit down as soon as he could… Otherwise he was probably going to collapse. Henry might not have been a prideful individual but he'd prefer if he at least appeared to be a hero instead of a victim.

The other Keyblade wielder didn't only sling magic around in ways that both of his moms would be impressed with, but he also had some physical fighting techniques that were pretty awesome. He didn't use his Keyblade like a sword as Henry tried to, and his actual moves didn't look like the smooth techniques that would suggest formal instruction, but it was clear he was experienced. And some of the flips and floating looked cool.

Was this guy even human?

At last, all the monsters were exploded or whatever and Henry stumbled over to sit on the curb. "Thanks, I think you saved my life."

"No problem, It's- Wait, you have a Keyblade?!" The brunet's mouth dropped open comically.

"What, you didn't notice before?" Henry now had the time to study the guy. He was probably only a couple years older than him and had bizarrely spiky hair. Like Henry was seriously questioning how hair gel like that existed to create such and utter anime hair. His clothing was also odd, which confirmed that he was from so other world.

"Nah," he said, looking closely at the key, "I guess not."

"You have one too."

"Well, I thought I knew everyone who had a Keyblade," the other boy suddenly looked him in the eyes piercingly, which was more than a little freaky. Henry was starting to feel uncomfortable when the hard blue eyes turned relieved and then back to friendly. It was like the moment of- _suspicion?_ \- had never happened. "I'm Sora."

"Henry," he smiled shakily,

"Henry…" Sora's eyes lit up, "Your family _just_ sent me to get you. Regina said you'd be in some mansion? No one mentioned you had a Keyblade."

"It's… a new development. It just showed up when those monsters attacked me."

"The Heartless," Sora provided, "They're kind of like the darkness in hearts."

Henry didn't know how, especially with how flush he was from nearly passing out, but he was pretty sure he went pale. This was connected to Emma. It had to be.

"So why did a Keyblade show up?" He needed to know. It was far better than dwelling on just what monsters made of darkness were made from.

Sora shrugged, his keyblade disappearing with a flash of light. Then he put his arms up and rested the back of his head on his interlaced palms. "You chosen by the Keyblade. That's what I was told when the same thing happened to me."

"I still don't know what a Keyblade is."

Sora looked like he wanted to laugh but merely smiled, "I'd tell you if I knew myself. The current story is that each Keyblade is a piece of the χ-blade, but I don't know for sure since you exist. But Keyblades are the only weapon that can kill Heartless, and they can unlock everything. They can also transform."

That just led to more questions… At least that explained what happened with the car. Henry studied his Keyblade, trying to see how a giant key was somehow powerful. It still felt right in his hands, even while completely exhausted, like it was a part of him. He ran a finger over the 'flames' of the blade.

"Where's my family?" Henry forced himself away from his Keyblade. It was just hard to focus.

"They were heading to some place called Gold's Shop? David said you knew where that was."

"Yeah… Is everyone ok?"

"Yep!" Sora smiled so cheerily that Henry would have believed it was his own family, "And Kairi healed them up anyways."

Henry nodded but found the movement was not kind to his pounding head.

"Are you ok, Henry?" His concern was genuine.

"I'm just… tired."

"Here," Sora called back out his Keyblade. Henry was nervous when it was pointed at him but then Sora said "Cura!" and everything was better. Like magic his head was clear and he was ready for action. With amazement he looked at his arms that had been scratched and bruised to find he was completely healed.

"You have got to show me how to do that- Thank you!" He leapt to his feet, amazed he wasn't at least a little lightheaded.

"I suppose I could show you a few things on the way to your family…" Sora scratched his head,

"This is gonna be awesome!"

That snapped Sora out of uncertainty and into enthusiasm. "Yeah, this'll be fun!"

"Totally."

* * *

A/N: So, after years of going THAT'S JUST LIKE KINGDOM HEARTS! I'm finally doing it. I've crossing them over. This is set early season 5 for OUAT and during hypothetical KH3 time. I meant to do this as a oneshot but as it's not even half done I suppose it wasn't to be. I am going to attempt to write this quickly though, before OUAT directly makes a part of this against cannon. It's only going to be two or three chapters in total, so I promise I'm not going to leave it hanging.

Next: So, why has Emma's hair turned white when she went to the dark side? Is there something Nort-y in the future?


End file.
